From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C57FC47095 for ; Wed, 9 Jun 2021 07:37:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21B7C61351 for ; Wed, 9 Jun 2021 07:37:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232524AbhFIHjo (ORCPT ); Wed, 9 Jun 2021 03:39:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:50700 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230233AbhFIHjn (ORCPT ); Wed, 9 Jun 2021 03:39:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623224269; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dKHLpYCGx0g7EoGipPcjgNbmX1MLZSaTZNKvZi1Yge0=; b=BanBmrlkWiESpeBlPJUeA7gBEPRBbrNZ8f8svdOhUDKSjJMyYtFyIrkW3QjAbI4ua8VbNo ceikR63Qiby7QAnQdrfaebr4fpctVrX5tRB4qj3thEG30m/jsEEP0LmXs/HNhvPQuiq7TF mwvOAlvhJun4HdOonNRzkg4fZsFaNQA= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-142-92_3efykO7K_GP0hrYtFYw-1; Wed, 09 Jun 2021 03:34:36 -0400 X-MC-Unique: 92_3efykO7K_GP0hrYtFYw-1 Received: by mail-qt1-f198.google.com with SMTP id a5-20020ac84d850000b029024998e61d00so2028397qtw.14 for ; Wed, 09 Jun 2021 00:34:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=dKHLpYCGx0g7EoGipPcjgNbmX1MLZSaTZNKvZi1Yge0=; b=GjdIMaBro2sNnYPVK3TdFo8oIEmr/eflMeeTJMKN2J7xK/dNl3rg2yyAk2NM8rahBx Slq0R167qKW3iEQL3iwZuJua39mtmK7GPV/cdxf5AuJlfj/KhYLejEvaXzWzttbbZZvu yLv/hX4vAnM8TkU1GW38g/UCyplZza4NMRwlgJQwX4y39w0mSAseqy8EWuqEhmeGTkVi bA5tAjocOfH5+5XOWQn3GWE8FkGOYmYrb6ubHY+gTR/CqAysOIYw7RqgO8BomZVDcs+R 9vTb8fXE+yi4JqM9q+s72ntmMQQs/MEEIy8foRhMB2UwB3wUwacndLa6s5Hr9QW3RgU9 0i+A== X-Gm-Message-State: AOAM530SsS6U5nK95WggaTl0j1FoJd6SoHAwuN5DRrxiGTGJWpwt8b72 PFlDKons3oXTmJw8j+8kg6zBreLfSOCnj/ohm48yP7Y8Vef70x3z+PTm9i6TvfWjJqVhWzszr1q 4fHv/c92BBjU4ckTw X-Received: by 2002:a05:620a:1253:: with SMTP id a19mr11372148qkl.365.1623224076136; Wed, 09 Jun 2021 00:34:36 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyeQ3vZwJD5V9+1RCCrE3JekeNNLTpi7d82jJPwWzCuGoj9yPBCBVWCXy2YNny96QDa4zPseQ== X-Received: by 2002:a05:620a:1253:: with SMTP id a19mr11372138qkl.365.1623224075940; Wed, 09 Jun 2021 00:34:35 -0700 (PDT) Received: from [192.168.0.106] ([24.225.235.43]) by smtp.gmail.com with ESMTPSA id g19sm6014609qto.49.2021.06.09.00.34.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 09 Jun 2021 00:34:35 -0700 (PDT) Subject: Re: [PATCH net-next] net: tipc: fix FB_MTU eat two pages To: Menglong Dong Cc: ying.xue@windriver.com, David Miller , Jakub Kicinski , LKML , netdev , tipc-discussion@lists.sourceforge.net, Menglong Dong , Zeal Robot References: <20210604074419.53956-1-dong.menglong@zte.com.cn> <998cce2c-b18d-59c1-df64-fc62856c63a1@redhat.com> <20210607125120.GA4262@www> <46d2a694-6a85-0f8e-4156-9bb1c4dbdb69@redhat.com> <20210609025412.GA58348@www> From: Jon Maloy Message-ID: <927af5e7-6194-d94e-1497-6b3dce26c583@redhat.com> Date: Wed, 9 Jun 2021 03:34:33 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210609025412.GA58348@www> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 6/8/21 10:54 PM, Menglong Dong wrote: > On Tue, Jun 08, 2021 at 06:37:38PM -0400, Jon Maloy wrote: >> > [...] >> I spent a little more time looking into this. I think the best we can do is >> to keep FB_MTU internal to msg.c, and then add an outline function to msg.c >> that can be used by bcast.c. The way it is used is never time critical. >> >> I also see that we could need a little cleanup around this. There is a >> redundant align() function that should be removed and replaced with the >> global ALIGN() macro. >> Even tipc_buf_acquire() should use this macro instead of the explicit method >> that is used now. >> In general, I stongly dislike conditional code, and it is not necessary in >> this function. If we redefine the non-crypto BUF_TAILROOM to 0 instead of 16 >> (it is not used anywhere else) we could get rid of this too. >> >> But I leave that to you. If you only fix the FB_MTU macro I am content. >> > Yeah, I think I can handle it, just leave it to me. > > (finger heart :/) > Menglong DongI It seems like I have been misleading you. It turns out that these messages *will* be sent out over the nework in some cases, i.e. at multicast/broadcast over an UDP bearer. So, what we need is two macros, one with the conditional crypto head/tailroom defined as you first suggested, and one that only use the non-crypto head/tailroom as we have been discussing now. The first one can be defined inside bcast.c, the latter  inside msg.c. It might also be a good idea to give the macros more descriptive names, such as ONEPAGE_MTU in the broadcast version, and ONEPAGE_SKB in the node local version. Does that make sense? ///jon >